Boosting international trade may not be the best way to improve food security, as it makes many countries vulnerable to food shortages caused by market fluctuations, according to new research.

A study published on 11 May in Proceedings of the National Academy of Sciences found that countries heavily reliant on importing their food — including many in the Arab world and Latin America — are more exposed to environmental and market shocks than those where at least half of all food is home-grown.

As the global population grows and agricultural production reaches the planet’s maximum capacity, food trade systems can destabilise more easily as small shocks in food supply will impact more people, the study warns.

"It challenges the idea that all trade is good," says Paolo D'Odorico, environmental scientist at the University of Virginia in the United States, and one of the study’s authors. "We depend on trade but at the same time we need to be aware that it makes the whole food system vulnerable to crisis."

D’Odorico and his team analysed trade and food production data from 140 countries between 1986-2010. They used computer modelling to simulate how small changes in population affect the quantity of food that is available through a combination of local production and trade.

Countries that rely on imports are much more vulnerable to food pressures caused by population growth and they find it harder to secure their food supply than exporting countries or those where imports and exports are roughly equal, the researchers found. Much of North Africa, the Middle East and Latin America fall into this vulnerable category, they say.

“We depend on trade but at the same time we need to be aware that it makes the whole food system vulnerable to crisis.”

Paolo D'Odorico, University of Virginia

Also, the number of countries deemed at risk of food shortages has ballooned during the last 25 years — whilst at the same time the planet witnessed an explosion in international trade, the paper states.

This increase in global food trade was caused in part by innovations in agriculture that allow for more food production and preservation.

David Debucquet, a senior research fellow at the International Food Policy Research Institute in Washington, United States, says trade can be a help, not a hindrance, to food security, as it triggers the development of technology.

The potential for companies to recoup the cost of developing innovations through global expansion helps drive their research and attracts foreign investment in national food systems, he says.

D'Odorico, on the other hand, believes that creating sufficient stockpiles of food in import countries is the most effective safeguard against shocks in food availability, such as natural disasters and bad harvests. Global grain stocks have fallen by ten per cent since 1990 as a result of easier access through trade, and are now only able to fulfil a fifth of annual demand, according to the paper. Rebuilding these stocks must be a top priority for governments to safeguard against food shortages, says D’Odorico.